The present disclosure relates to approaches for reformulating red pyrotechnic compositions so as to eliminate environmentally objectionable perchlorate ingredients while still providing acceptable performance when compared to in-service signal flare devices.
Pyrotechnics are used in a variety of applications. One such application is colored signal flares. Many such pyrotechnic flare compositions include chlorate or perchlorate oxidizers. Residual perchlorates from these devices may be absorbed into groundwater and require remediation.
In the past, the vast majority of red, green and yellow signal flares have used perchlorate ingredients to produce their desired colors. This has contributed to an increase in the total concentration of perchlorate residues at various military and industrial sites, and to generally higher than desired concentration in drinking water supplies. Clearly, any methods that can be used to eliminate the perchlorates and minimize any other chlorine-containing ingredients would be an environmentally noteworthy advance in the state of the art.
The U.S. Army has fielded a red star cluster. The red star cluster includes magnesium powder fuel, strontium nitrate oxidizer, polyvinyl chloride (PVC) color enhancer, and binder. The binder includes Laminac 4116, Lupersol DDM binder, and cobalt naphthenate.
The U.S. Navy has an in-service red flare composition (IS RED 1). IS RED 1 includes Granulation 18 magnesium fuel, potassium perchlorate, strontium nitrate, asphaltum, and binder. The binder including Laminac 4110 epoxy and Lupersol DDM curing agent. Accordingly, it was these and other perchlorate-free compositions that formed the starting point in the new perchlorate-free red signal flare formulations disclosed in the present patent application.